A Fresh Approach to the Design of Clean Engines for the Performance Motorcycle Market 2007-32-0001

Until the early to mid 1990's the engine of choice for off road and recreational vehicles were mainly 2-stroke engines due to the superior power density and Wide Open Throttle (WOT) torque characteristics. With the introduction of increasingly more stringent emission control requirements there has been a large swing to 4-stroke engines. In recent years there has been significant development to improve the power density of the 4-stroke engine in an effort to match the performance 2-stroke engine, however at a compromise to the torque characteristics and the manufacturing and maintenance cost of the engine. This paper looks at a fresh approach to develop a new concept engine to deliver a better compromise between the 4-stroke and existing carburettor 2-stroke characteristics, and provides early experimental results from the development work for a preferred WOT torque characteristic.